Sum 41 frontman Deryck Whibley has been hospitalized after he was attacked in a bar brawl in Japan on Thursday night.

The band flew out to the Far East earlier this week and are due to take to the stage at the Summersonic Music Festival in Osaka this weekend. However, their appearance has been thrown into doubt after Whibley was assaulted by three unidentified assailants.

Avril Lavigne's ex-husband was admitted to a local hospital, where he is currently being treated, although the extent of his injuries and his condition were unknown as WENN went to press.

Breaking the news to fans on the band's Twitter.com page in the early hours of Friday, a rep wrote, "Deryck Whibley was attacked in a bar last night by 3 unknown people. He is in the hospital now. Japanese police are looking into the matter."

Whibley was still under doctors' care on Friday afternoon, when the group released an update on their official website.  The statement reads: "It is unfortunate to say, but Deryck Whibley is still in the hospital. He was attacked late last night in Japan. We are waiting for results and we are hoping for the best. Thanks for your support."

The incident is the latest interruption in the Canadian rockers' world trek - the band was forced to cancel a number of dates on the Warped Tour in the U.S. after Whibley came down with bronchitis, according to the Hollywood Reporter.

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